U.S. patent number 6,380,518 [Application Number 09/921,139] was granted by the patent office on 2002-04-30 for heat treatment apparatus and substrate processing system.
This patent grant is currently assigned to Tokyo Electron Limited. Invention is credited to Nobuyuki Sata, Eiichi Shirakawa.
United States Patent |
6,380,518 |
Shirakawa , et al. |
April 30, 2002 |
Heat treatment apparatus and substrate processing system
Abstract
The heat treatment apparatus of the present invention comprises
a chamber, a hot plate for supporting and heating a substrate in a
chamber, a gas supply mechanism having a single or a plurality of
gas blow-out ports and arranged in an upper space above the hot
plate in the chamber, for supplying a gas along the substrate so as
to cover the substrate placed on the hot plate, and an exhaust
mechanism having a single or a plurality of gas converge/exhaust
ports which face the gas blow-out ports with the hot plate
interposed therebetween, for converging and exhausting the gas
blown out from the gas blow-out ports, from the chamber, the gas
converge/exhaust ports having an effective exhaustion opening
length L2 which is shorter than an effective blow-out opening
length L1.
Inventors: |
Shirakawa; Eiichi (Kumamoto,
JP), Sata; Nobuyuki (Kumamoto, JP) |
Assignee: |
Tokyo Electron Limited (Tokyo,
JP)
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Family
ID: |
27290106 |
Appl.
No.: |
09/921,139 |
Filed: |
August 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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251731 |
Feb 18, 1999 |
6291800 |
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Foreign Application Priority Data
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Feb 20, 1998 [JP] |
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10-039327 |
Feb 20, 1998 [JP] |
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10-039328 |
Feb 23, 1998 [JP] |
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10-040246 |
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Current U.S.
Class: |
219/390; 118/724;
118/725; 118/728; 219/405; 219/411; 392/416; 392/418 |
Current CPC
Class: |
G03F
7/168 (20130101); G03F 7/40 (20130101); H01L
21/67109 (20130101) |
Current International
Class: |
G03F
7/40 (20060101); G03F 7/16 (20060101); H01L
21/00 (20060101); F27B 005/14 () |
Field of
Search: |
;219/390,405,411
;118/724,725,720,728,50.1 ;392/416,418 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Walberg; Teresa
Assistant Examiner: Fuqua; Shawntina
Attorney, Agent or Firm: Rader, Fishman & Grauer
Parent Case Text
This is a division of application Ser. No. 09/251,731, filed Feb.
18, 1998 now U.S. Pat. No. 6,291,800.
Claims
What is claimed is:
1. An heat treatment apparatus comprising:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
a first pipe having a single or a plurality of gas blow-out ports
for supplying a gas along the substrate so as to cover the
substrate placed on the hot plate in an upper space above the hot
plate in the chamber;
first and second exhaust ports facing both ends of the first pipe
with the hot plate interposed therebetween;
a second pipe interposed between the first and second exhaust
ports;
a third and fourth exhaust ports facing both ends of the second
pipe with the hot plate interposed therebetween, the first pipe
being arranged between the third and fourth exhaust ports;
a gas supply system communicating with the first and second pipes
for supplying a gas to each of the first and second pipes;
an exhaust system communicating with the first, second, third, and
fourth exhaust ports, for exhausting the gas through each of the
exhaust ports;
a first switching unit for selectively switching the communication
between one of the first and second pipes and the gas supply
system;
a second switching unit for selectively switching the communication
between either a pair of the first and second exhaust ports or a
pair of the third and fourth exhaust ports, and the exhaust system;
and
a control section connected to the first and second switching
units, for alternately switching a first connection state for
flowing the gas from the first pipe to the first exhaust port with
a second connection state for flowing the gas from the first pipe
to the second exhaust port, and for alternately switching a third
connection state for flowing the gas from the second pipe to the
third exhaust port with a fourth connection state for flowing the
gas from the second pipe to the fourth exhaust port as well as for
alternately switching a first and second connection state with the
second switching means.
2. An heat treatment apparatus comprising:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
an exhaust mechanism having a single or a plurality of exhaust
ports for exhausting a gas in a direction substantially parallel to
a main surface of the substrate placed on the hot plate;
a gas supply mechanism facing the exhaust ports with the hot plate
interposed therebetween and having gas blow-out ports whose total
length involved in blowing out of the gas is greater than that of
the exhaust ports; and
an air board for guiding the gas blown out from the gas brow-out
ports to the exhaust ports.
3. The apparatus according to claim 2, wherein the air board
consists of
a first board member extended from an end of an array of gas
blow-out ports to an end of an array of the exhaust ports, and
a second board member extended from the other end of the array of
the gas blow-out ports and the other end of the array of the
exhaust ports.
4. The apparatus according to claim 2, further comprising:
a sensor for detecting temperature of the hot plate; and
control means for controlling at least one of the gas supply
mechanism and the exhaust mechanism on the basis of the temperature
detected by the sensor.
5. The apparatus according to claim 2, further comprising gas
flow-rate changing means for changing a flow rate of the gas blown
out from the gas blow-out ports.
6. The apparatus according to claim 5, wherein the gas flow-rate
changing means has
an opening diameter control means for controlling an opening
diameter of the gas flow-out port;
a sensor for detecting temperature of the hot plate; and
control means for controlling the opening diameter control means on
the basis of the temperature detected by the sensor.
7. The apparatus according to claim 2, further comprising gas
blow-out angle changing means for changing an angle of blowing out
the gas blown out from the gas blow-out ports.
8. The apparatus according to claim 7, wherein
the gas blow-out changing means has
angle control means for controlling an angle of the gas blow-out
ports,
a sensor for detecting temperature of the hot plate; and
control means for controlling the angle control means on the basis
of the temperature detected by the sensor.
9. A substrate processing system comprising:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
an exhaust mechanism having a single or a plurality of exhaust
ports for exhausting a gas substantially in parallel with a main
surface of the substrate placed on the hot plate;
a gas supply mechanism facing the exhaust ports with the hot plate
interposed therebetween and having a gas blow-out ports whose total
length involved in blowing out of the gas is greater than that of
the exhaust ports;
a housing having triangular-prism corner assemblies each having a
triangular bottom surface whose apex corresponds to the exhaust
port and whose bottom line corresponds to the gas blow-out ports,
for surrounding the hot plate;
a plurality of heat treatment units symmetrically arranged in the
housing;
a main arm mechanism surrounded by the heat treatment units, for
transporting the substrate to each of the heat treatment units;
and
control means for controlling the main arm mechanism and the heat
treatment units, independently.
10. The substrate processing system according to claim 9,
wherein
the heat treatment units consist of four units each being arranged
at a corner of the chamber in a plan view.
11. The substrate processing system according to claim 9, wherein a
most inner part of each of the corner assemblies is formed with a
right angle in a plan view and the exhaust port is arranged in the
most inner part.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a heat treatment apparatus and a
substrate processing system incorporated in a resist
coating/developing system for heating or cooling a substrate such
as a semiconductor wafer or an LCD (liquid crystal display)
substrate.
In a photolithography process for manufacturing a semiconductor
device, a photoresist is coated on the substrate and the
resist-coated film is exposed to light and developed. The series of
processes is carried out in the resist coating/developing system
constituted of heating units such as a prebake unit and a post bake
unit. Each of these heating units has a hot plate having a built-in
heater of a resistance heating type. In the peripheral portion of
the hot plate, a plurality of small projections are provided. The
substrate is supported by these small projections, so that a small
space is created between the substrate and the hot plate. The
substrate is heated by receipt of heat radiation (heat energy
beams) emitted from the hot plate.
At this time, air around the hot plate is heated and raised in
temperature. The hot air thus heated rises up within a chamber and
exhausted through an exhaust port formed through-an upper cover.
The hot air comes into an ascending air stream which flows from the
outer peripheral portion of the hot plate toward the center and is
converged and exhausted from a position right above the substrate.
As a result, part of particles contained in the air may fall down
on the substrate, causing a problem of particle adhesion.
In addition a conical-form recess is formed around the exhaust port
in the lower surface portion of the cover. The hot air is guided
along the conical-form recess, formed into a spiral air stream and
flows toward the exhaust port. However, the flow of the hot air
tends to stagnate near right below the exhaust port. The stagnant
hot air has a thermal influence upon the wafer W, rendering
temperature of the wafer W non-uniform.
Furthermore, the height from the floor to the ceiling of the clean
room is limited to a certain range. Therefore, it is necessary to
reduce the height of the apparatus. However, a conventionally-used
heat treatment apparatus has the upper cover, so that the height of
the apparatus is large.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to:provide a small heat
treatment apparatus capable of heating a substrate uniformly while
preventing particles from being attached to the substrate.
The heat treatment apparatus according to the present invention
comprises:
a chamber;
a hot plate for supporting and heating a substrate in a
chamber;
a gas supply mechanism having a single or a plurality of gas
blow-out ports and arranged in an upper space above the hot plate
in the chamber, for supplying a gas along the substrate so as to
cover the substrate placed on the hot plate; and
an exhaust mechanism having a single or a plurality of gas
convergent exhaust ports which face the gas blow-out ports with the
hot plate interposed therebetween, for converging and exhausting
the gas blown out from the single or the plurality of the gas
blow-out ports, from the chamber, the single or the plurality of
the gas convergent exhaust ports having an effective exhaustion
opening length L2 which is shorter than an effective blow-out
opening length L1.
The heat treatment apparatus further comprises a control section
for controlling the gas supply mechanism and the exhaust mechanism
to form gaseous streams which flow in substantially parallel to an
upper surface of the substrate from the single or the plurality of
the gas blow-out ports to the single or the plurality of the gas
convergent exhaust ports, in the upper space above the
substrate.
The exhaust mechanism has two convergent exhaust ports arranged at
a distance, and further comprising a switching mechanism for
switching exhaust operation between the two convergent exhaust
ports.
The gas blow-out ports consist of a plurality of holes arranged
lengthwise along a linear pipe which is at least longer than a
diameter of the substrate, and
the convergent exhaust ports consists of at least three convergent
exhaust holes arranged so as to face the linear pipe at an equal
distance from the linear pipe;
The heating treatment apparatus further comprises switching means
for switching the exhaust operation between the at least three
exhaust holes.
Furthermore, the heat treatment apparatus comprises an open/shut
mechanism for opening and shutting the convergent exhaust holes
individually.
The control section selects some holes from the convergent exhaust
holes and instructs the open/shut mechanism to open the convergent
exhaust holes selected.
The heat treatment apparatus further comprises a parallel moving
mechanism for moving the convergent exhaust holes in parallel with
the linear pipe.
The control section controls operation of the switching mechanism
to gradually switch gaseous-steam directions from the gas blow-out
ports toward the convergent exhaust holes.
The heat treatment apparatus further comprises exhaust port moving
means for moving the convergent exhaust ports along the gas
blow-out ports so as to continuously switch the gaseous-stream
directions from the gas blow-out ports toward the convergent
exhaust ports.
The chamber has upper and lower surfaces substantially closed and a
lateral surface having an opening formed therein for
loading/unloading the substrate.
The heat treatment apparatus according to the present invention
comprises:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
a first pipe having a single or a plurality of gas blow-out ports
for supplying a gas along the substrate so as to cover the
substrate placed on the hot plate in an upper space above the hot
plate in the chamber;
first and second exhaust ports facing both ends of the first pipe
with the hot plate interposed therebetween;
a second pipe interposed between the first and second exhaust
ports;
a third and fourth exhaust ports facing both ends of the second
pipe with the hot plate interposed therebetween, the first pipe
being arranged between the third and fourth exhaust pipes;
a gas supply system communicating with the first and second pipes
for supplying a gas to each of the first and second pipes;
an exhaust system communicating with the first, second, third, and
fourth exhaust ports, for exhausting the gas through each of the
exhaust ports;
a first switching unit for selectively switching the communication
between one of the first and second pipes and the gas supply
system;
a second switching unit for selectively switching the communication
between either a pair of the first and second exhaust ports or a
pair of the third and fourth exhaust ports, and the exhaust system;
and
a control section connected to the first and second switching
units, for alternately switching a first connection state for
flowing the gas from the first pipe to the first exhaust port with
a second connection state for flowing the gas from the first pipe
to the second exhaust port, and for alternately switching a third
connection state for flowing the gas from the second pipe to the
third exhaust port with a fourth connection state for flowing the
gas from the second pipe to the fourth exhaust port, as well as for
alternately switching a first and second connection state with the
second switching means.
The heat treatment apparatus according to the present invention
comprises:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
gaseous stream formation means for supplying a gas along the
substrate so as to cover the substrate placed on the hot plate and
for exhausting the gas, thereby forming a gas flowing region in a
triangle or trapezoid form in an upper space above the hot plate in
the chamber, in a plan view; and
gaseous stream switching means for switching a directions of
gaseous streams formed by the gaseous stream formation means.
The gaseous stream formation means comprises three porous pipes for
blowing out the gas in successive different directions which differ
by an angle of 120.degree.;
means for switching supply of the gas to the three porous pipes;
and
exhaust ports each facing the corresponding porous pipe with the
hot plate interposed therebetween.
In this case, each of the three porous pipes is formed straight and
arranged in the triangular form so as to surround the hot plate;
and
the exhaust ports are located respectively at three apexes of the
triangle formed of the porous pipes.
Furthermore, in this case, three porous pipes each having an arc
shape and arranged in a ring form so as to surround the hot plate
in a plan view; and
the exhaust ports are positioned at three joints between the porous
pipes.
The gaseous stream formation means has four porous pipes for
blowing out the gas in successive directions which differ by an
angle of 90.degree., means for switching gas supply to the four
porous pipes, and exhaust ports each facing the corresponding
porous pipe with the hot plate interposed therebetween.
The four porous pipes each being formed straight and arranged in a
square form so as to surround the hot plate, in a plan view,
and
the exhaust ports are positioned respectively at four apexes of the
square formed of the porous pipes.
The four porous pipes each having an arc shape and arranged in a
ring form so as to surround the hot plate, in a plan view, and
the exhaust ports are positioned respectively at four joints of the
ring formed of the porous pipes.
The gaseous stream formation means comprises
a circular rail concentrically arranged around the hot plate;
an arc form pipe moving on the circular rail for blowing out the
gas inwardly to a center of the hot plate;
an exhaust port member moving on the circular rail, for exhausting
the gas; and
moving means for synchronously moving the exhaust port member and
the arc-shape pipes with the hot plate interposed therebetween.
The heat treatment apparatus according to the present invention
comprises:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
an exhaust mechanism having a single or a plurality of exhaust
ports for exhausting a gas in a direction substantially parallel to
a main surface of the substrate placed on the hot plate;
a gas supply mechanism facing the exhaust ports with the hot plate
interposed therebetween and having gas blow-out ports whose total
length involved in blowing out of the gas is greater than that of
the exhaust ports; and
an air board for guiding the gas blown out from the gas brow-out
ports to the exhaust ports.
The air board consists of
a first board member extended from an end of an array of gas
blow-out ports to an end of an array of the exhaust ports, and
a second board member extended from the other end of the array of
the gas blow-out ports and the other end of the array of the
exhaust ports.
Furthermore, the heat treatment apparatus of the present invention
comprises:
a sensor for detecting temperature of the hot plate; and
control means for controlling at least one of the gas supply
mechanism and the exhaust mechanism on the basis of the temperature
detected by the sensor.
The substrate processing system according to the present invention
comprises:
a chamber;
a hot plate for supporting and heating a substrate in the
chamber;
an exhaust mechanism having a single or a plurality of exhaust
ports for exhausting a gas substantially in parallel with a main
surface of the substrate placed on the hot plate;
a gas supply mechanism facing the exhaust ports with the hot plate
interposed therebetween and having a gas blow-out ports whose total
length involved in blowing out of the gas is greater than that of
the exhaust ports;
a housing having triangular-prism corner assemblies each having a
triangular bottom surface whose apex corresponds to the exhaust
port and whose bottom line corresponds to the gas blow-out ports,
for surrounding the hot plate;
a plurality of heat treatment units symmetrically arranged in the
housing;
a main arm mechanism surrounded by the heat treatment units, for
transporting the substrate to each of the heat treatment units;
and
control means for controlling the main arm mechanism and the heat
treatment units, independently.
The heat treatment units consist of four units each being arranged
at a corner of the chamber in a plan view.
The most inner part of each of the corner assemblies is formed with
a right angle in a plan view and the exhaust port is arranged in
the most inner part.
According to the present invention, air streams containing dust
lost their speed in front of the exhaust ports, it is possible to
prevent the dust from falling on the substrate to form particles.
In addition, it is possible to prevent non-uniform heating of the
substrate without causing stagnation of the air on the substrate.
Furthermore, it is possible to reduce the height of the treatment
apparatus.
Additional objects and advantages of the invention will be set
forth in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate presently preferred
embodiments of the invention, and together with the general
description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
FIG. 1 is a schematic plan view of a resist coating/developing
system;
FIG. 2 is a schematic front view of the resist coating/developing
system;
FIG. 3 is a schematic back view of the resist coating/developing
system;
FIG. 4 is a perspective sectional view of a heat treatment
apparatus according to Embodiment 1 of the present invention, as
viewed from the upper side;
FIG. 5 is a perspective sectional view of the heat treatment
apparatus according to Embodiment 1 of the present invention, as
viewed from the lateral side;
FIG. 6 is a perspective sectional view of the heat treatment
apparatus according to Embodiment 1, whose upper portion is
partially broken away;
FIG. 7 is a block diagram showing a control system of the heat
treatment apparatus according to Embodiment 1;
FIG. 8 is a schematic plan view showing air streams within the heat
treatment apparatus of Embodiment 1;
FIG. 9 is another schematic plan view showing air streams within
the heat treatment apparatus according to Embodiment 1;
FIG. 10 is a schematic plan view showing air streams according to a
first modified example of Embodiment 1;
FIG. 11 is a schematic plan view showing air streams according to a
second modified example of Embodiment 1;
FIG. 12 is a schematic plan view showing air streams according to a
third modified example of Embodiment 1;
FIG. 13 is a schematic plan view showing air streams according to a
fourth modified example of Embodiment 1;
FIG. 14 is a perspective sectional view of a heat treatment
apparatus according to Embodiment 2 of the present invention, as
viewed from the upper side;
FIG. 15 is a perspective sectional view of the heat treatment
apparatus according to Embodiment 2 of the present invention, as
viewed from the lateral side;
FIG. 16 is a perspective sectional view of the heat treatment
apparatus according to Embodiment 2, whose upper portion is
partially broken away;
FIG. 17 is a block diagram showing a control system of the heat
treatment apparatus according to Embodiment 2;
FIG. 18 is a schematic plan view showing air streams within the
heat treatment apparatus according to Embodiment 2;
FIG. 19 is another schematic plan view showing air streams within
the heat treatment apparatus according to Embodiment 2;
FIG. 20 is still another schematic plan view showing air streams
within the heat treatment apparatus according to Embodiment 2;
FIG. 21 is a perspective sectional view of the heat treatment
apparatus according to a first modified example of Embodiment 2, as
views from the upper side;
FIG. 22 is a perspective sectional view of the heat treatment
apparatus according to a second modified example of Embodiment 2,
as views from the upper side;
FIG. 23 is a perspective sectional view of the heat treatment
apparatus according to a third modified example of Embodiment 2, as
views from the upper side;
FIG. 24 is a perspective sectional view of the heat treatment
apparatus according to a fourth modified example of Embodiment 2,
as views from the upper side;
FIG. 25 is a schematic plan view showing air streams within a heat
treatment apparatus according to Embodiment 3 of the present
invention;
FIG. 26 is a block diagram showing a control system of the heat
treatment apparatus according to Embodiment 3;
FIG. 27 is a perspective sectional view of the heat treatment
apparatus according to a modified example of Embodiment 3, as
viewed from the upper side; and
FIG. 28 is a schematic plan view of the baking system having a
plurality of treatment units according to Embodiment 3.
DETAILED DESCRIPTION OF THE INVENTION
Now, various preferred embodiments of the present invention will be
explained with reference to the accompanying drawings.
As shown in FIGS. 1 to 3, a coating/developing system 1 has a
load/unload section 10, a process section 11, and an interface
section 12. The load/unload section 10 has a cassette table 20 on
which cassettes CR each storing e.g., 25 semiconductor wafers W,
are loaded/unloaded. The process section 11 has various single
wafer processing units for processing wafers W sequentially one by
one. The interface section 12 is interposed between the process
section 11 and a light-exposure apparatus (not shown).
Four projections 20a are formed on the cassette table 20. Four
cassettes CR are positioned respectively at right places to the
process section 11 by means of these projections 20a. Each of the
cassettes CR mounted on the table 20 has a load/unload opening
facing the process section 11.
In the load/unload section 10, a first sub-arm mechanism 21 is
formed which is responsible for loading/unloading the wafer W
into/from each cassette CR. The first sub arm mechanism 21 has a
holder portion for holding the wafer W, a back and forth moving
mechanism (not shown) for moving the holder portion back and forth,
an X-axis moving mechanism (not shown) for moving the holder
portion in an X-axis direction, a Z-axis moving mechanism (not
shown) for moving the holder portion in a Z-axis direction, and a
.theta. rotation mechanism (not shown) for swinging the holder
portion around the Z-axis.
The first sub-arm mechanism 21 can gain access to an alignment unit
(ALIM) and an extension unit (EXT) belonging to a third process
unit group G3.
As shown in FIG. 3, a main arm mechanism.22 is liftably arranged at
the center of the process section 11. Five process units G1-G5 are
arranged around the main arm mechanism 22. The main arm mechanism
22 is arranged within a cylindrical supporting body 49 and has a
liftable wafer transporting apparatus 46. The cylindrical
supporting body 49 is connected to a driving shaft of a motor (not
shown). The driving shaft can be rotated about the Z-axis in
synchronism with the wafer transporting apparatus 46 by an angle of
.theta.. The wafer transporting apparatus 46 has a plurality of
holder portions 48 movable in a front and rear direction of a
transfer base table 47.
Units belonging to first and second process unit groups G1, G2, are
arranged at the front side of the system 1. Units belonging to a
third process unit group G3 are arranged next to the load/unload
section 10. Units belonging to a fourth process unit group G4 are
arranged next to the interface section 12. Units belonging to a
fifth process unit group G5 are arranged at a back side of the
system 1.
As shown in FIG. 2, the first process unit group G1 has two
spinner-type process units for applying a predetermined treatment
to the wafer W mounted on a spin chuck within the cup CP. In the
first process unit G1, for example, a resist coating unit (COT) and
a developing unit (DEV) are stacked in two stages sequentially from
the bottom. In the second process unit group G2, two spinner type
process units such as a resist coating unit (COT) and a developing
unit (DEV), are stacked in two stages sequentially from the bottom.
The resist coating unit (COT) is preferably set at a lower stage
than the developing unit (DEV). This is because a discharge line
for the resist waste solution is desired to be shorter than a
developing waste solution since the resist waste solution is more
difficult to discharge than the developing waste solution. However,
if necessary, the resist coating unit (COT) may be arranged at the
upper stage than the developing unit (DEV).
As shown in FIG. 3, the third process unit group G3 has a cooling
unit (COL), an adhesion unit (AD), an alignment unit (ALIM), an
extension unit (EXT), a prebaking unit (PREBAKE), and postbaking
unit (POBAKE). These units are stacked sequentially from the
bottom.
Similarly, the fourth process unit group G4 has a cooling unit
(COL), an extension cooling unit (EXTCOL), an extension unit (EXT),
a cooling unit (COL), a prebaking unit (PREBAKE) and a postbaking
unit (POBAKE). They are stacked sequentially from the bottom.
As mentioned, it is preferable that the cooling unit (COL) and the
extension cooling unit (EXTCOL) to be operated at low processing
temperatures, be arranged at lower stages and the baking unit
(PREBAKE), the postbaking unit (POBAKE) and the adhesion unit (AD)
to be operated at high temperatures, be arranged at the upper
stages. With this arrangement, thermal interference between units
can be reduced.
At the front side of the interface section 12, a movable pick-up
cassette CR and an non-movable buffer cassette BR are arranged in
two stages. At the back side of the interface section 12, a
peripheral light exposure apparatus 23 is arranged. At the center
portion of the interface section 12, a second sub-arm mechanism 24
is provided, which is movable independently in the X and Z
directions, and which is capable of gaining access to both
cassettes CR and BR and the peripheral light exposure apparatus 23.
In addition, the second sub-arm mechanism 24 is rotatable around
the Z-axis by an angle of .theta. and is designed to be able to
gain access not only to the extension unit (EXT) belonging to the
fourth processing unit G4 but also to a wafer transfer table (not
shown) near the light exposure apparatus (not shown).
In the system 1, the fifth processing unit group G5 can be arranged
at the back side of the main arm mechanism 22. The fifth processing
unit G5 can be slidably shifted in the Y-axis direction along a
guide rail 25. Since the fifth processing unit group G5 can be
shifted as mentioned, maintenance operation can be applied to the
main arm mechanism 22 easily from the back side.
Now, referring to FIGS. 4 and 5, we will explain the prebaking unit
(PREBAKE) and the postbaking unit (POBAKE) belonging to the third
and fourth process units G.sub.3, G.sub.4.
The prebaking unit (PREBAKE) is a heat treatment apparatus for
heating a photoresist film to at least higher temperature than room
temperature before subjecting to the light exposure process. The
postbaking unit (POBAKE) is a heat treatment apparatus for heating
the photoresist film to at least higher temperature than room
temperature after the light exposure. The chamber 52 of each of the
heat treatment apparatuses has a inoperable ceiling 56a, an
openable closed floor 56b. Although lateral walls 52a, 52b are
inoperable, lateral walls 52c and 52d are openable.
A hot plate 58 is fitted at a center opening of the chamber floor
56 and supported by a supporting plate 76. The hot plate 58 has
three holes 60 threading through it. Three lift pins 62 are
inserted into the corresponding three holes 60. Three lift pins 62
are connected to and supported by an arm 80, which is further
connected to and supported by a rod 84a of a vertical cylinder 84.
When the rod 84a is allowed to protrude from the cylinder 84, the
lift pins 62 protrude from the hot plate 58, thereby lifting the
wafer W.
A linear pipe 64 is arranged horizontally along the first lateral
wall 52a. The linear pipe 64 extends in the Y-axis direction and
communicates with a supply port of a gas (air) supply system 91. A
plurality of nozzle holes 63 are arranged lengthwise along the
linear pipe 64. Air or a nitrogen gas is blown out almost
horizontally from each of the nozzle holes 63.
Two exhaust pipes 66a and 66b thread through the second lateral
wall 52b. Openings of the exhaust ports 65a, 65b are thus present
within the chamber 52. Each of the exhaust ports 65a, 65b faces to
the nozzle holes 63 of the linear pipe 64. Each of two exhausting
pipes 66a, 66b communicates with the exhaust system 92 via a
switching unit 93. The exhaust port 65a is arranged at one of the
corners formed of the lateral walls 52b and 52d. The exhaust port
65b is arranged at another corner formed of the lateral walls 52b
and 52c. The distance between the exhaust ports 65a and 65b is
nearly equal to the length of the linear pipe 64.
The opening diameters and shapes of all nozzle holes 63 may be
identical or not identical. More specifically, the opening diameter
of the nozzle hole 63 may be the smallest at the center portion of
the pipe 64 and gradually increased toward the right and left end
portions of the pipe 64. Conversely, the opening diameter of the
nozzle hole 63 may be the largest at the center portion of the pipe
64 and gradually decreased toward the right and left end portions
of the pipe 64. Alternatively, a structure capable of changing the
opening diameter and a gas flow-out angle of each of the nozzle
holes 63, may be employed.
The gas flow-out angle of the nozzle holes 63 may be changed by
inclining the nozzle holes 63 present at the center of the
longitudinal direction of the pipe 64 toward the exhaust port 65a
or 65b in place of proceeding straight. If so, the gas can be
prevented from hitting directly upon the hot plate 58 close to the
linear pipe 64.
Furthermore, the gas supply system 91 and an exhaust system 92 may
be controlled on the basis of the detected temperature of the hot
plate 58. For example, when the detected temperature of the hot
plate 58 is extremely low, operations of the gas supply system 91
and the evacuation system 92 are independently controlled to
prevent the decrease in temperature of the hot plate.
A ring form shutter (not shown) is attached so as to surround the
hot plate 58. Loading/unloading ports 50A, 50B are formed in the
chamber lateral walls 52c, 52d, respectively. The wafer W is loaded
into and unloaded from the chamber 52 by the main arm mechanism 22
through the loading/unloading port 50A, 50B after the shutter is
opened.
The shutter (not shown) is liftably supported by a cylinder 82 via
an arm 78. The shutter is positioned at a stand-by position lower
than the hot plate 58 during non-operation time, whereas, during
operation time, it is lifted up to a position higher than the hot
plate 58 and shuts up the openings 50A, 50B. When the shutter 66 is
lifted up, nitrogen gas or air blows out from the holes 63 of the
pipe 64 into an upper space 59 of the chamber.
As shown in FIG. 5, the exhausting pipes 66a, 66b thread through a
chamber floor 56b and a bottom plate 72 and extend downwards. A
machine chamber 74 is arranged below the chamber floor 56b. The
machine chamber 74 is defined by the chamber floor 56b, lateral
walls 52a, 52b, 52c, 52d and the bottom plate 72. The machine
chamber 74 houses a hot plate supporting board 76, a shutter arm
78, lift pin arm 80, and liftable cylinders 82, 84.
Next, referring to FIG. 7, a control system of the heat treatment
apparatus will be explained.
A heater 96 consisting of a resistance heating type is buried in
the hot plate 58. The heater 96 is connected to a power supply
source (not shown) housed in a controller 94. The hot plate 58 is
equipped with a sensor 97. Temperature of the hot plate 58 is
detected by the sensor 97 and a signal of the detected temperature
is input into the controller 94. The controller determines how much
power should be supplied to the heater 96 on the basis of the
temperature detection signal thus input. As the sensor 97, a
thermocouple and a platinum resistance heater (Pt sensor) may be
used alone or in combination thereof. Alternatively, the substrate
W may be heated by circulating a vaporized heat medium within the
hot plate 58, in place of the resistance heater.
The gas supply system 91 has a gas (air) inlet port (not shown) for
introducing a gas (air) from a clean room, a filter (not shown) for
removing an alkaline composition such as ammonia from the air, a
filter (not shown) for removing particles from the air, a
ventilation fan (not shown), and a gas supply port communicating
with the pipe 64 (not shown). A power supply switch for the fan is
connected to the controller 94. The linear pipe 64 extends straight
in parallel with the chamber wall 52a. A plurality of holes 63 are
formed lengthwise along the pipe 64. These holes 63 are arranged
longitudinally in line along the pipe 64 and responsible for
flowing out the air horizontally therefrom.
The exhaust system 92 has an inlet port (not shown) for sucking the
hot air of the chamber 52, an exhaust blower (not shown), and
either a plant intensive exhaust unit (not shown) or an exhaust
port (not shown) communicating with the gas supply system 91. When
a circulation route is formed so as to communicate with the exhaust
port of the exhaust system. 92 and a gas inlet port of the gas
supply system 91, a heat exchanger (not shown) is attached to the
circular route to cool the hot air. The withdraw port of the
exhaust system 92 is communicated with two exhaust pipes 66a, 66b
via the switching unit 93. The exhaust pipe 66a threads through the
chamber wall 52b and the exhaust port 65a of the pipe 66a is
present at one of the corners of the chamber 52. The exhaust pipe
66b threads through the chamber wall 52b and the exhaust port 65b
of the pipe 66b is present at the other corner of the chamber
52.
The switching unit 93 has a confluence pipe 66c having passages
each communicating with the exhaust pipes 66a and 66b, and a switch
damper (not shown). A power switch of the-drive section for the
switch damper is connected to the controller 94.
The controller 94, which is not shown in FIG. 7, is connected to
both a power supply switch of the driving motor 84 for moving the
lift pins 62 and a power supply switch (not shown) for an open/shut
driving cylinder for the shutters 50A, 50B. Furthermore, a keyboard
(not shown) for data input is connected to an input portion of the
controller 94, for inputting data of heat treatment conditions for
each lot.
Now, referring to FIGS. 8 and 9, we will explain the case where the
photoresist film coated on the wafer W is treated with heat by
using the heat treatment, apparatus.
When a main switch of the coating/developing system 1 is turned on,
power is initiated to supply to each heating unit from the
corresponding power source. When the hot plate 58 becomes stable at
a predetermined temperature, the wafer W is transported by the main
arm mechanism 22 to the prebaking unit. The surface of the wafer W
is coated with photoresist. The arm holder 22a is inserted into the
chamber 52 after the shutter is opened. The pin 62 is then moved up
to transfer the wafer W from the arm holder 22a onto the pins 62.
Then, the arm holder 22a is withdrawn from the chamber 52 and the
pins 62 are moved down to place the wafer W on the hot plate 58. At
this time, the controller 94 controls the heater 96 in such a way
that the hot plate 58 is set at a desired temperature, on the basis
of the detection signal sent from the sensor 97. In this manner,
the hot plate 58 is maintained at, for example, 120.degree. C. When
the temperature detected by the sensor 97 is beyond an acceptable
range, the power supply to the heat 96 is controlled or a flow
amount and rate of the air (gas) sent from the pipe 64 toward the
hot plate 58 are controlled.
Subsequently, operations of the gas supply system 91 and the
exhaust system 92 are individually initiated thereby forming
gaseous streams from the first lateral wall 52a toward the second
lateral wall 52b. The gaseous streams flow almost horizontally in
the upper space 59 and move differently if the functioning exhaust
port is switched. More specifically, gaseous streams from the
linear pipe 64 toward the first exhaust port 65a are formed as
shown in FIG. 8. When the flow route of exhaust air is switched
from the first exhaust pipe 66a to the second exhaust pipe 66b by
the switching unit 93, gaseous streams from the linear pipe 64
toward the second exhaust port 65b are formed as shown in FIG. 9.
As described, the flow route of the exhaust is switched by the
switching unit 93 between the first exhaust pipe 66a and the second
exhaust pipe 66b at predetermined time intervals.
The air stream obtained by changing the exhaust ports alternately
is called as "virtually parallel streams flowing in the X-axis
direction". Since the "virtually parallel streams" are formed in
the upper space 59, heat can be given from the hot plate 58 to the
wafer W uniformly, applying the treat treatment uniformly over the
upper surface of the wafer W.
According to the heat treatment apparatus of this embodiment, even
if particles are mixed in the air stream, the gaseous streams do
not slow down in speed nor stagnate. The particles therefore do not
fall onto the wafer W, with the result that contamination of the
wafer W with the particles adhesion is avoided.
According to the heat treatment apparatus of this embodiment, the
space 59 above the hot plate 58 can be narrowed. Therefore the size
of the apparatus in the Z-axis direction can be reduced,
contributing to miniaturization of the heat treatment
apparatus.
Now, referring to FIG. 10, another embodiment of the present
invention will be explained. Note that further explanation is
omitted as to the same structural elements of this embodiment as
those of the embodiment mentioned above.
In the heat treatment apparatus of this embodiment, seven exhaust
ports 67a-67g are arranged at regular intervals along the second
lateral wall 52b. These exhaust ports 67a-67g communicate with the
exhaust system 92 (not shown). An open/shut unit 95 is interposed
between the exhaust system 92 and the exhaust ports 67a-67g. The
open/shut unit 95 is responsible for opening and shutting the
communication between each of the exhaust ports 67a-67g and the
exhaust system under control of the controller 94.
According to the heat treatment apparatus, the air stream can be
exhausted from an exhaust port arbitrarily chosen from the exhaust
ports 67a-67g. For example, if the exhaust ports 67a-67d are only
opened by the open/shut unit 95 and air is exhausted from them, the
resultant air steams is formed into a trapezoidal flowing region.
In this case, an effective exhaustion opening length L2 of the
exhaust ports 67a-67d is shorter than an effective opening blow-out
opening. length L1 of the nozzle holes 63. The wording "effective
exhaustion opening length L2" used herein refers to the lateral
length of exhaust ports array (67a-67d) capable of inhaling the air
at the same time. On the other hand, the wording "the effective
blow-out opening length L1" used herein refers to the lateral
length of a plurality of air blow-out ports (nozzle hole array 63)
capable of blowing out the air at the same time.
According to this embodiment, a spiral stream is rarely generated
near the exhaust ports. It is preferred to render the effective
exhaustion opening length longer, since the occurrence of the
spiral steam decreases.
In this embodiment, if exhaust ports to be involved in exhaustion
of the air are sequentially switched from the first exhaust port
67a to the second exhaust port 67b and from the second exhaust port
67b to the third exhaust port 67c, the directions of gaseous
streams can be changed little by little. As described, if the
directions of the gaseous streams are sequentially changed, the
gaseous streams become stable. As a result, the wafer W can be
uniformly treated with heat.
Referring now to FIG. 11, another embodiment of the present
invention will be described. Note that explanation will be omitted
as to the same structural elements of this embodiment as those of
the aforementioned embodiments.
In the heat treatment apparatus of this embodiment, the exhaust
port of the exhaust pipe 66A is supported by a moving mechanism
(not shown) movable in the Y-axis direction along the second wall
52b. The moving mechanism has a crank, a motor applying rotational
driving force to the crank, and a reciprocating slider linked to
the crank. The exhaust port of the exhaust pipe 66A is reciprocally
moved along the second lateral wall 52b by the moving mechanism.
The exhaust port of exhausting pipe 66A of the exhaust system (not
shown) is connected to a pipe 66c by means of a flexible pipe 98.
Thus, the pipe 98 can move in accordance with the movement of the
exhaust port of the exhaust pipe 66.
As described, since the directions of the gaseous streams are
changed slowly by switching the position of the exhaust port of the
exhaust pipe 66A, the spiral stream rarely occurs. As a result, the
wafer W is uniformly treated with heat.
Now, referring to FIG. 12, another embodiment of the present
invention will be explained. Note that explanation will be omitted
as to the same structural elements of this embodiment as those of
the aforementioned embodiments.
In the heat treatment apparatus of this embodiment, a second linear
pipe 64b is arranged along the second lateral wall 52b so as to
face a first linear pipe 64a. Exhaust ports of the pipes 68a, 68b
are arranged at both ends of the second linear pipe 64b,
respectively. Exhaust ports of export pipes 68c, 68d are also
arranged at both ends of the first linear pipe 64a, respectively.
The first linear pipe 64a is operated in couple with the exhaust
pipes 68a, 68b by the controller 94. Similarly, the second linear
pipe 64b is operated in couple with the exhaust pipes 68c, 68d.
If the exhaust pipes 68a and 68b are operated alternately while the
air is allowed to flow from the first linear pipe 64a, virtually
parallel streams (heading to the right in FIG. 12) to the wafer can
be formed. On the other hand, if the exhaust pipes 68c, 68d are
operated alternately while the gas is allowed to flow from the
second linear pipe 64b, virtually parallel streams flowing in a
reverse direction (heading toward the left in FIG. 12) can be
obtained. The switching operation is performed by operating a
switching unit (not shown) on the basis of a control signal sent
from the controller 94.
According to the heat treatment apparatus, the directions of the
virtually parallel streams can be reversed from the right to the
left and vise versa, thermal unbalance to be generated between the
upstream and the downstream of the gaseous streams is successfully
prevented. Therefore, the heat treatment is performed more
uniformly.
Referring now to FIG. 13, another embodiment of the present
invention will be explained. Note that explanation will be omitted
as to the same structural elements of this embodiment as those of
the aforementioned embodiments.
The heat treatment apparatus of this embodiment, a first group of
nozzle holes 69a-69o are arranged in line along the first lateral
wall 52a. A second group of nozzle holes 70a-70o are arranged in
line along the second lateral wall 52b. The first and second
nozzles holes 69a-69o, 70a-70b communicate with the gas supply
system 91 (not shown) as well as the exhaust system 92 (not shown).
A switching unit (not shown) is interposed between the gas supply
system 91 and the exhaust system 92. The switching unit is
responsible for operating the gas supply system 91 and the exhaust
system 92 independently and switching them to each other on the
basis of the control signal sent from the controller 94.
According to the heat treatment apparatus mentioned above, the
direction of the virtually parallel streams can be reversed. It is
possible to prevent thermal unbalance generating between the
upstream and the downstream. Therefore, the heat treatment can be
performed uniformly.
In the aforementioned heat treatment apparatus, it is not necessary
to arrange the nozzle holes and the exhaust pipe independently. It
is therefore possible to simplify the structure of the apparatus
and to miniaturize the apparatus.
Now, referring to FIGS. 14 to 24, Embodiment 2 of the present
invention will be explained. Note that explanation will be omitted
as to the same structural elements of this embodiment as those of
the aforementioned embodiments.
As shown in FIGS. 14 and 15, a circular through-hole 56 is formed
at near the center of a shielding board 55. The upper portion of
the hot plate 58 is exposed to the treatment space 59 between the
shielding board 55 and a ceiling board 57 through the circular hole
56. A linear pipe 64 and air boards 107, 108 are arranged so as to
surround the hot plate 58 to form an equilateral triangle in the
treatment space 59. Accordingly, the hot plate 58 is located at the
center of the equilateral triangle. The linear pipe 64 extends in
the X-axis direction along the third lateral wall 52c and arranged
in the upper portion of the treatment space 59. When air is blown
out from the nozzle holes 63, the air stream is passed through the
upper region of the hot plate 58.
As shown in FIG. 16, three linear pipes 110, 115, 120 are arranged
in the form of an equilateral triangle so as to surround the hot
plate 58. The hot plate 58 is located at the center of the
equilateral triangle formed of pipes 110, 115 and 120. A number of
nozzle holes 112 are formed in the lateral portion of the first
linear pipe 110. The air is designed to be blown out virtually
horizontally from each of the nozzle holes 112. A number of nozzle
holes 119 are formed in the lateral portion of the second linear
pipe 115. The air is blown out from each of the nozzle holes 119
virtually horizontally. Also, a number of nozzle holes 121 are
formed in the lateral portion of the third linear pipe 120. The air
is blown out almost horizontally from each of the nozzle holes
121.
As shown in FIG. 17, the air is supplied from the gas supply system
91 and selectively distributed to three pipes 134, 135, 136 by the
switching unit 127. The air is further sent to linear pipes 110,
115, 120 via inlet ports 111, 116, 126, respectively, and blown out
from each of nozzle holes 112, 119, 121. Air boards 113, 118, 122
are respectively formed on the lateral surfaces of the linear pipes
110, 115, 120, respectively.
The first linear pipe 110 is closed at both ends and communicated
with the gas inlet port 111 which is formed in the close proximity
with one of the ends. The gas inlet port 111 communicates with the
gas supply system 91 by way of the pipe 136 and the switching unit
127. The first, second, and third linear pipes 110, 115, 120 have
substantially the same structures.
As shown in FIG. 18, the air board 113 is attached to the lateral
surface of the first linear pipe 110 in order to regulate the shape
of the air stream. More specifically, the air board 113 regulates
the air stream into virtually an equilateral triangular gas flowing
region 99 above the hot plate 58. The air board 113 is formed of a
long and narrow rectangular board and has through holes 113a
communicating with the nozzle holes 112. These through holes 113a
are located in the lateral surface of the air board 113
corresponding to the nozzle holes 112 so as to communicate the
holes 112. With this structure, the air blown out from the nozzle
holes 112 flows through the through hole 113a toward the hot plate
58.
Exhaust ports 123, 124, 125 are formed respectively at three apexes
of substantially triangular gas flowing region 99. These exhaust
ports 123, 124, 125 communicate with the exhaust system 91 by way
of the switching unit 127, thereby exhausting the air from the
chamber 52.
In this embodiment, opening diameters and shapes of the nozzle
holes 112, 119, 121 are set completely identical. However, if the
opening diameters and shapes of the nozzle holes are appropriately
changed, the gas flowing region can be formed easily and smoothly
in substantially the triangular form. For example, the opening
diameters of the linear pipes 110, 115, 120 may be the smallest
near the center and gradually increased toward the right and left
ends of the pipe. Conversely, the opening diameter of the linear
pipes may be the largest near the center and gradually decreases
toward the right and left ends.
Now, referring to FIG. 17, the control system of the apparatus
according to this embodiment will be explained.
The control system has the heater 96, the sensor 97, three linear
pipes 110, 115, 120, two switching units 127, 129, the gas supply
system 91, the exhaust system 92, and the controller 94. The heater
96 is buried in the hot plate 58. The first switching unit 127 has
a switching circuit which communicates with the gas supply system
91 and each of three pipes 134, 135, 136. The switching circuit is
responsible for selecting one of three pipes 134, 135, 136 to allow
it to communicate with the gas supply system 91. The pipes 134,
135, 136 are arranged between the switching unit 129 and the
exhaust port 123, between the switching unit 127 and the exhaust
port 124, and between the switching unit 127 and exhaust port 125,
respectively. The switching unit 127 involved in exhaustion, which
is responsible for switching the connection between the exhaust
system 92 and the exhaust ports 123, 124, 125, is further connected
to the controller 94. Therefore, the exhaust process is integrally
controlled by the controller 94.
Although not shown in FIG. 17, the pins 62 protruding or
withdrawing from the upper surface of the hot plate 58 and a
driving system for driving a door (not shown) for opening/shutting
the housing opening portion (loading and unloading port) 50A, 50B
are also connected to the controller 94. Furthermore, a power
supply circuit of the main wafer W transportation mechanism 22 is
connected to the controller 94.
On the other hand, upon initiation of the power supply, the power
source of the heater 96 within the hot plate 58 is turned on,
thereby initiating heating of the hot plate 58. The hot plate 59 is
controlled so as to become stable at a predetermined temperature
while detecting temperature of the hot plate 58 by the sensor
97.
When the temperature of the hot plate 58 becomes stable at the
predetermined temperature, the wafer W is transported by the main
wafer transportation mechanism 22 onto the hot plate 58 thus
heated.
As a next step, the operations of the gas supply system 91 and the
exhaust system 92 are initiated, with the result that gaseous
streams are formed above the hot plate 58.
Next, referring to FIGS. 18 to 20, we will explain gaseous streams
formed in the region above the hot plate 58.
As shown in FIG. 18, the air is simultaneously blown out from the
nozzle holes 121 of the third linear pipe 122, converged at a third
corner, and exhausted through the third exhaust port 123. As shown
in FIG. 19, the air is simultaneously blown out from the nozzle
holes 112 of the first linear pipe 113, converged at a first
corner, and exhausted through the first exhaust port 124. As shown
in FIG. 20, the air is simultaneously blown out from the nozzle
holes 119 of the second linear pipe 118, converged at a second
corner, and exhausted through the second exhaust port 125.
In the initial stage of the heat treatment, the gas supply system
91 is communicated with the pipe 134 by operating the switching
unit 127 on the basis of the instruction from the controller 94. In
this way, the air is sent into the linear pipe 120; at the same
time, the exhaust system 92 is communicated with the pipe 131 by
the switching unit 129.
As shown in FIG. 18, the air is supplied from the gas supply system
91 to the linear pipe 120 by the switching unit 127, and blown out
from the nozzle holes 121 into the chamber 52. Furthermore, the air
is blown out from the nozzle holes 121 toward the exhaust port 123,
converged at the exhaust port 123, and exhausted. At this time,
since the exhaust port 131 is communicated with the exhaust system
92 by the second switching unit 129, a negative pressure given by
the exhaust system 92 acts on the exhaust port 131. Therefore, the
gas blown out from each of the nozzle holes 121 flows toward the
exhaust port 123.
The air blown out from the nozzle holes 121 of the center portion
of the pipe flows straight or near straight. On the other hand, the
air blown out from the nozzle holes 121 in the close proximity with
both ends of the pipe flows out straight (at virtually a right
angle to the pipe 120) from the nozzle holes 121 but immediately
hit upon the air boards 113, 118. The air proceeding direction is
corrected by the air boards 113, 118 and guided along the air
boards 113, 118, into the exhaust port 123. As a result, the
gaseous streams draw radial lines converged into the exhaust port
123 and substantially in parallel with the surface of the air
boards 113, 118, as shown in FIG. 18.
As described, the exhaust port 123 and the linear pipe 120 are
arranged so as to sandwich the hot plate 58 above the hot plate 58
in the heating treatment apparatus. In addition, the air boards
113, 118 are provided so as to guide the air stream from both ends
of the nozzle hole array 121 formed in the lateral side of the
linear pipe 120, into the exhaust port 123. As a result, the gas
blown out from the nozzle hole 121 is led along the air boards 113,
118 to form a virtually triangular gas flowing region 99 above the
hot plate 58. In the gas flowing region 99, the adjacent gaseous
streams moves straight while keeping regular intervals between
them. As a result, neither spiral nor stagnant gaseous streams
occur, contributing to uniform heating.
The gas supply system 91 is communicated with the pipe 136 by the
first switching unit 127; at the same time, the exhaust system 92
is communicated with the pipe 132 by the second switching unit 129.
When flow passage is changed by the first and second switching
units 127, 129, the air blows out from the nozzle holes 112 almost
in perpendicular to the linear pipe 110, then regulated by the air
boards 118, 122, forms into the gas flowing region 99 of virtually
a triangular form, as shown in FIG. 19.
Furthermore, the gas supply system 91 is allowed to communicate
with the pipe 135 by the first switching unit 127; at the same
time, the exhaust system 92 is allowed to communicate with the
exhaust pipe 133 by the second switching unit 129. When the flow
passage is changed by the first and second switching units 127,
129, the air is blown out from the nozzle holes 119 in almost
perpendicular to the linear pipe 115. The gaseous streams are then
regulated by the air boards 113, 122 to form the gas flowing region
99 in the form of virtually a triangle as shown in FIG. 20.
According to the apparatus of this embodiment, even if particles
are contained in the gaseous streams flowing through the upper
space 59, neither speed loss nor stagnation of gaseous streams
occurs. It follows that the particle will not fall upon the wafer W
and thus not adhere on the wafer W in the heat treatment
chamber.
In the apparatus of this embodiment, the directions of the gaseous
streams are sequentially switched in three different directions by
switching the communications of the exhaust system 92 with the
exhaust ports 123, 124, 125. In this manner, unbalance in heat
supply amount between the upper and lower portion of the gaseous
streams can be canceled out. The heat treatment is applied
uniformly over the entire surface of the wafer W.
Furthermore, three linear pipes 110, 115, 120 are arranged in the
triangular form so as to surround the hot plate 58. These three
linear pipes 110, 115, 120 act as a flow-regulating plate for
regulating the gaseous streams.
In the apparatus of this embodiment, the gaseous streams flow in
parallel with the upper surface (wafer W) of the hot plate 58, so
that the upper space 59 can be narrower above the hot plate 58. It
follows that the height of the entire heat treatment apparatus can
be reduced. As a result, the entire heat treatment apparatus can be
miniaturized.
In the aforementioned embodiments, a heating-type heat treatment
apparatuses for heating the wafer W are explained as examples.
However, the present invention can be applied to a cooling-type
heat treatment apparatus.
Referring now to FIGS. 21 to 24, the heat treatment apparatus
according to another embodiment of the present invention will be
explained. Note that explanation will be omitted as to the same
structural elements of this embodiment as those of the
aforementioned embodiments.
As shown in FIG. 21, three arc-form pipes 140, 141, 142 surround
the hot plate 58 to form a single ring, in the heat treatment
apparatus of this embodiment. The ring is concentric with a circle
of the hot plate 58. Each of the pipes 140, 141, 142 communicates
with the gas supply system 91 (not shown) via the switching unit
127 (not shown).
The third exhaust port 148 is formed between the first arc-form
pipe 140 and the second arc-form pipe 141. The first exhaust port
146 is formed between the second arc-form pipe 141 and the third
arc-form pipe 142. The second exhaust port 147 is formed between
the first arc-form pipe 140 and the third arc-form pipe 142. In
short, the first arm-form pipe 140 faces the first exhaust port 146
with the hot plate 58 interposed between them. The second arc-form
pipe 141 faces the second exhaust port 147 and the third arc-form
pipe 141 faces the third exhaust port 147. The exhaust ports 146,
147, 148 communicate with the exhaust system 92 (not shown) by the
switching unit 129 (not shown).
In the lateral inner surfaces of the arc-form pipes 140, 141, 142,
numeral nozzle holes 143, 144, 145 are respectively perforated
vertically. These nozzle holes 143, 144, 145 face the center of the
hot plate 58. Therefore, the air blown out from the nozzle holes
143, 144, 145 are easily converged at the exhaust ports 146, 147,
148 respectively. The air flow is easily rendered stable.
The three arc-form pipes 140, 141, 142 are combined to form a ring.
The space occupied by the gas supply mechanism is therefore
reduced. The apparatus can be miniaturized.
As shown in FIG. 22, four linear pipes 150, 151, 152, 153 are
arranged in a square form so as to surround the hot plate 58 in a
plan view. Furthermore, four exhaust ports 154, 155, 156, 157 are
arranged around the hot plate 58. The first pipe 150 faces the
first exhaust port 155 with the hot plate interposed between them.
The second pipe 151 faces the second exhaust port 156 with the hot
plate interposed between them. The third pipe 152 faces the third
exhaust port 157 with the hot plate 58 interposed between them. The
fourth pipe 153 faces the fourth exhaust port 154 with the hot
plate 58 interposed between them.
The pipes 150, 151, 152, 153 are communicated with the gas supply
system 91 (not shown) via the switching unit 127 (not shown). The
exhaust ports 154, 155, 156, 157 communicate with the exhaust
system 92 (not shown) via the switching unit 129 (not shown). By
switching the flow route by the first and second switching units
127, 129, four air steams, that is, the air stream flowing from the
pipe 150 to the exhaust port 155, the air stream flowing from the
pipe 151 to the exhaust port 156, the air stream flowing from the
pipe 152 to the exhaust port 157, and the air stream flowing from
the pipe 153 to the exhaust port 154, can be sequentially
switched.
According to this embodiment, the air stream can be switched in the
four directions having an angle of 90.degree., 180.degree.,
270.degree., and 360.degree. to the hot plate 58. Therefore, the
heat treatment is applied uniformly to the wafer W.
As shown in FIG. 23, four arc-form pipes 160, 161, 162, 163 are
arranged in a ring form so as to surround the hot plate 58 in a
plan view. Furthermore, four exhaust ports 164, 165, 166, 167 are
arranged around the hot plate 58. The first pipe 160 faces the
first exhaust port 165 with the hot plate 58 interposed between
them. The second pipe 161 faces the second exhaust port 166 with
the hot plate 58 interposed between them. The third pipe 162 faces
the third exhaust port 167 with the hot plate 58 interposed between
them. The fourth pipe 163 faces the fourth exhaust port 164 with
the hot plate 58 interposed between them.
The pipes 160, 161, 162, 163 are communicated with the gas supply
system 91 (not shown) by way of the switching unit 127 (not shown).
The exhaust ports 164, 165, 166, 167 communicate with the exhaust
system 92 (not shown) via the switching unit 129 (not shown). By
switching the flow route from the first and second switching units
127, 129 and vise versa, the air stream flowing from the pipe 160
to the exhaust port 165, the air stream flowing from the pipe 161
to the exhaust port 166, the air stream flowing from the pipe 162
to the exhaust port 167, and the air stream flowing from the pipe
163 to the exhaust port 164 can be sequentially switched.
According to this embodiment, the four arc-form pipes 160, 161,
162, 163 are arranged in the ring form, so that the space occupied
by the pipes is reduced, contributing to miniaturization of the
apparatus.
As shown in FIG. 24, a rail 173 is arranged around the hot plate
concentrically therewith. On the rail 173, two sliders 170, 172
slidably move clockwise. The slider 170 is formed of an arc-form
pipe having a plurality of gas blow-out holes 170a. The slider 172
is formed of a block having an exhaust port 171. The sliders 170
and 172 are moved synchronously by the controller 94 so as to face
each other at all times. Incidentally, as a member for the gas
supply mechanism, a square pipe may be used in place of a round
pipe. In this case, the square pipe is preferably used since the
lateral surface of the square pipe can be used as the air
board.
Now, referring to FIGS. 25 to 28, another heat treatment apparatus
according to another embodiment of the present invention will be
explained. Note that explanation will be omitted as to the same
structural elements of this embodiment as those of the
aforementioned embodiments.
As shown in FIG. 25, a linear pipe 184 is arranged along the
lateral wall 52c in the upper space 59. The linear pipe 184 extends
in the X-axis direction and a plurality of nozzle holes 183 for
blowing out the gas are arranged along the longitudinal direction
of the pipe. A gas such as air or an inert gas is supplied from the
gas supply system (not shown) to the linear pipe 184. In the close
proximity with the lateral wall 52d, an exhaust port 185, which
communicates with the exhaust mechanism (not shown), is arranged so
as to face the linear pipe 184 with the hot plate interposed
between them.
Two air boards 187, 188 are arranged extending from the linear pipe
184 to the exhaust port 185. The upper space 59 is partitioned by
the air boards 187, 188. More specifically, the air board 187
extends from near one end portion of the linear pipe 184 to close
proximity with the exhaust port 185. The air board 188 extends from
near the other end portion of the linear pipe 184 to the close
proximity with the exhaust port 185. These air boards 187, 188 are
responsible for guiding the gas blown out from the nozzle holes 183
of the linear pipe 184 to the exhaust port 185 to thereby regulate
the shape of the gas flowing region 99 in a virtually triangular
form. Each of these air boards 187, 188 is formed of a long and
narrow board and fitted to the ceiling 56a of the chamber.
According to this embodiment, since the air flows smoothly in the
gas flowing region 99, neither spiral nor stagnant streams occur.
As a result, the wafer W is heated uniformly by the hot plate
58.
Incidentally, the opening diameter and the gas blow-out angle of
the nozzle holes 183 may be freely varied. In the case, the
aperture and the gas blow-out angle are controlled on the basis of
the detection temperature of the hot plate 58. More specifically,
when the temperature of the hot plate in a close proximity with the
linear pipe 64 is significantly reduced, the opening diameters of
the nozzle holes 183 near the center of the linear pipe 184 are
reduced, whereas the opening diameters of the nozzle holes 183 near
both ends of the linear pipe 184 are increased.
Furthermore, in the case where temperature of the hot plate 58 near
the linear pipe 184 is significantly reduced, an angle of the
nozzle holes 183 located near the center thereof is changed so as
to direct toward the air board 187 or 188 in place of
straightforward direction in order for the air steams not in direct
contact with the portion of the hot plate 58 near the linear pipe
64.
Now, referring to FIG. 26, the control system of the heat treatment
apparatus will be explained.
A temperature sensor 97 and the main arm mechanism 22 are connected
to an input side of the controller 94. On the other hand, the gas
supply system 91, the exhaust system 92, the heater 96, and the
main arm mechanism 22 are connected to an output side of the
controller 94. The controller 94 controls operations of the gas
supply system 91 and the exhaust system 92 on the basis of the
detection temperature of the hot plate 58 and the timing for
loading/unloading the wafer W into/from the heat treatment
apparatus. As a result, desired gaseous streams are formed in the
upper space 59.
As shown in FIG. 27, a triangular prism corner assembly 200 having
an isosceles right triangular bottom may be employed in a corner
portion of the chamber of the heat treatment apparatus. The corner
assembly 200 has a hot plate 58, a front surface board 190, an
opening 191, lateral surface boards 192, 193, and an exhaust port
195. The opening 191 is defined by a pair of the front surface
boards 190. The holder 22a of the main arm mechanism 22 goes in and
out through the opening 191. In the opening 191, the linear pipe
184 is arranged. The air is blown out from the gas blow-out ports,
i.e., the nozzle holes 183 toward the exhaust port 195. The exhaust
port 195 is formed in the most inner part of the upper surface of
the corner assembly 200, as viewed from the opening side. The
exhaust port 195 faces the linear pipe 184 with the hot plate 58
interposed between them.
As shown in FIG. 28, four corner assemblies 200 may be provided in
a region to which the main arm mechanism 22 can gain access. If so,
a dead space within the heat treatment system can be used
effectively, contributing to the further miniaturization of the
substrate processing system.
Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects
is not limited to the specific details and representative
embodiments shown and described herein. Accordingly, various
modifications may be made without departing from the spirit or
scope of the general inventive concept as defined by the appended
claims and their equivalents.
* * * * *